EP1721694B1 - Method for producing at least one metal sheet element, method for producing at least one catalyst body, produced metal sheet element and catalyst body - Google Patents

Abstract

The production of a sheet metal element (1) to form a catalyst body for the catalytic treatment of gas, preferably exhaust gas from combustion engines, where the element corrugates with a corrugated vertex (1d), a metallic core, domains (53) with a coat (29) and exteriors of corrugated vertex with metallic polished domains (55), comprises applying a metallic oxide with a first coat material on the two surfaces of the metal element; removing the first coat material; and applying and developing the second coat material containing catalytic active material on the surface. The production of at least a sheet metal element (1) to form a catalyst body for the catalytic treatment of gas, preferably exhaust gas from a combustion engine, where the element corrugates with a corrugated vertex (1d), a metallic core, domains (53) with core covered with a coat and on exteriors of corrugated vertex with metallic polished domains (55), where at least a corrugate with two surfaces are arranged oppositely comprises applying at least a metallic oxide with a first coat material of the two surfaces of the metal element; removing the first coat material mechanically form the element; and applying and developing a second coat material containing catalytic active material on the surface. Independent claims are included for the following: (1) the production of at least one catalyst body comprising forming the sheet metal element or external sheet metal elements with adjacent sheet metal element layers, where at least a corrugate with corrugated vertices, metallic core and domains with core covered with a coat on the exterior corrugated vertex with metallic polished domains containing sheet metal element layers, which is arranged in corrugated vertex of adjacent layer with a contact domain, such that the metallic domains laying close with the layers are interconnected; (2) the sheet metal element obtained from the above process; and (3) a catalyst body with sheet metal element layers comprising sheet metal element.

Description

The invention relates to a method for producing at least one sheet metal element for forming at least one catalyst body for a catalytic treatment of gas, in particular exhaust gas of an internal combustion engine, namely a corrugated sheet metal element according to the preamble of claim 1.

The EP 0 049 489 A1 discloses a method for producing a catalyst body from two sheet metal elements, namely a sheet metal strip with trapezoidal waves and an originally flat sheet metal strip. The two metal strips are wound together to form a spiral winding, so that pairs of adjacent sheet metal layers arise, each consisting of a turn of one of the two metal strips. The two metal strips are soldered together at the wave crests of the corrugated metal strip and then provided with coatings containing noble metal. Since the coatings are applied only after winding and soldering the metal strips, results unevenly thick coatings. For example, the coatings become thicker in the corners formed by the contacting sheet metal bands than in areas lying between such corners. Uneven thicknesses of the coatings lead to the disadvantage that the catalytically active noble metal is not optimally distributed and can be exploited poorly.

From the EP 0 674 944 A1 and the corresponding US 5,628,925 It is known to apply to form a catalyst body such coatings on at least one smooth, wave-free metal strip and on at least one corrugated metal strip that sheet metal elements with bare, coating-free strip-shaped areas arise, which extend in the longitudinal direction of the metal bands and cross the waves in the finished catalyst body. The coating-free regions are produced by means of diaphragms during the application of the transition material or by first applying a release agent layer to the coating-material-free regions to be formed. This release agent layer may then either prevent the adhesion of the coating material or allow it to be removed by heating and blowing off. The coatings and bare areas having sheet metal elements are then wound or folded or stacked on each other, so that adjacent sheet metal element layers arise. These are firmly connected to one another at the wave crests by electron beam or laser or rolling wheel resistance welding or soldering.

When coating sheet metal elements, it is often desirable to sequentially apply multiple layers of a substantially alumina porous coating material, the so-called "wash coat" and then at least one precious metal to a sheet metal element and the sheet metal element between the various coating operations in an oven to heat. The formation of strip-shaped, coating-free areas with those from the EP 0 674 944 A1 and the US 5,628,925 However, known methods is very expensive even when applying only a single "wash coat" layer and in particular when applying several "wash coat" layers both when using diaphragms and when using a release agent. When applying In fact, "wash coat" must be arranged in the right places before applying a "wash coat" layer or new release agent layers must be applied. These known methods also have the disadvantage that the sheet metal elements also have coatings on the wave crests in addition to the coating-free areas, so that the coating-free areas of the adjacent sheet metal layers are at small distances apart even at the corrugation crests at least before joining the sheet metal element layers , This impairs the stability and durability of joints, especially welded joints. If sheet metal layers move relative to each other when using the catalyst body as a result of thermal stresses, vibrations and other accelerations, the movements may also cause abrasion of the coating material at the wave crests. Furthermore, according to the EP 0 674 944 A1 and US 5,628,925 produced catalyst body has the disadvantage that the coating-free areas also have lying between the adjacent wave peaks lying sub-areas that are quite large and, of course, no catalytic treatment of the exhaust gas.

The EP 1 300 555 A2 discloses catalyst bodies having alternating successive, planar and corrugated sheet metal layers. The flat sheet metal layers are partly completely blank and sometimes provided in places with coatings of catalytically active material. The corrugated sheet metal layers are all completely blank and lie with wave crests on completely bare, flat sheet metal element layers or on bare areas of locally provided with coatings, flat sheet metal layers. The EP 1 300 555 A2 however, does not disclose how the coatings are applied and coated areas are formed therebetween. Furthermore, the Catalyst body for partially burning a fuel and not provided for the purification of exhaust gas of an internal combustion engine. Since the channels or passages for the exhaust gas delimited by the corrugated and sheet-metal layers are bounded by areas which have large bare areas or are even completely bright and free of catalytically active material in certain passages, these catalyst bodies only bring about a low catalytic treatment the flowing through the passages exhaust gas and would not at all suitable for the catalytic purification of exhaust gas of an internal combustion engine.

The invention has for its object to provide a method for producing a wave, a metallic core, locally coatings and the apex bright, coating-free areas having sheet metal element, wherein the coatings at least one porous structure resulting metal oxide and a catalytically active material, for example at least one catalytically active noble metal to contain, and wherein the process is intended to avoid disadvantages of the known methods. The method should in particular be based on the EP 0 674 944 A1 make it possible, in a simple, cost-effective manner, to apply one or more layers of a coating material containing at least one metal oxide to form a porous coating and to create metallic bright areas at the desired locations. The metallic bright areas should be arranged such that after the completion of at least one sheet metal element sheet layers formed from one or more sheet metal elements and adjacent sheet metal layers can be stably and permanently connected to each other in metallic bright areas to a catalyst body with a desired, favorable, for example, uniform distribution of the catalytic active material and a high catalytic activity.

The object is achieved according to the invention by a method having the features of claim 1.

The invention further relates to a method for producing a catalyst body having the features of claim 9, a manufactured sheet metal element according to claim 13 and a prepared catalyst body according to claim 14.

Advantageous developments of the invention will become apparent from the dependent claims.

• Fig. 1 eine Draufsicht auf ein gewelltes Blechelement,
• Fig. 2 eine Seitenansicht einer Einrichtung zum Aufsprühen von erstem Überzugsmaterial auf ein gewelltes Blechelement,
• Fig. 3 eine Darstellung einer Einrichtung zum Erhitzen eines mit erstem Überzugsmaterial überzogenen Blechelements,
• Fig. 4 eine Einrichtung zur mechanischen Entfernung von Überzugsmaterial,
• Fig. 5 eine Einrichtung mit einem Bad zum Aufbringen von zweitem Überzugsmaterial auf ein Blechelement,
• Fig. 6 eine Schrägansicht von gewellten Blechelement-Lagen für die Bildung eines Katalysatorkörpers,
• Fig. 7 eine Seitenansicht einer Schweiss-Einrichtung zum Verschweissen von einem Stapel gewellter Blechelement-Lagen,
• Fig. 8 eine Seitenansicht eines Katalysatorkörpers,
• Fig. 9 einem Schnitt durch den Katalysatorkörper entlang der Linie IX - IX in Fig. 8,
• Fig. 10 einem Schnitt durch einen Abschnitt eines Katalysatorkörpers entlang der Linie X - X in Fig. 9, in grösserem Massstab,
• Fig. 11 eine Ansicht einer Anlage zum Verarbeiten von mehreren gewellten Blechelementen zu Blöcken mit verschweissten Blechelement-Lagen und
• Fig. 12 eine Schrägansicht eines Katalysatorkörpers mit mehreren Blöcken, die je einen Stapel verschweisster Blechelement-Lagen aufweisen.

The subject invention will be explained in more detail with reference to exemplary embodiments illustrated in the drawings. In the drawings show

• Fig. 1 a plan view of a corrugated sheet metal element,
• Fig. 2 a side view of a device for spraying first coating material on a corrugated sheet metal element,
• Fig. 3 a representation of a device for heating a coated with the first coating material sheet metal element,
• Fig. 4 a device for the mechanical removal of coating material,
• Fig. 5 a device with a bath for applying a second coating material to a sheet metal element,
• Fig. 6 an oblique view of corrugated sheet-metal layers for the formation of a catalyst body,
• Fig. 7 a side view of a welding device for welding a stack of corrugated sheet metal layers,
• Fig. 8 a side view of a catalyst body,
• Fig. 9 a section through the catalyst body along the line IX - IX in Fig. 8 .
• Fig. 10 a section through a portion of a catalyst body along the line X - X in Fig. 9 on a larger scale,
• Fig. 11 a view of a system for processing a plurality of corrugated sheet metal elements into blocks with welded sheet metal layers and
• Fig. 12 an oblique view of a catalyst body having a plurality of blocks, each having a stack of welded sheet element layers.

With regard to the drawings, it should also be noted that various figures are drawn diagrammatically and not to scale, and that in particular the various devices for processing sheet metal elements are shown in greatly simplified form.

For the production of a catalyst body, first at least one corrugated sheet metal element 1 is produced and provided, which consists exclusively of bare metal, for example stainless steel, and in Fig. 1 as well as in the left part of the Fig. 2 is apparent. The sheet metal element 1 is preferably band-shaped and thus formed from a sheet metal strip. The sheet metal element has two opposite surfaces 1a and two in plan view straight to each other parallel, first edges 1b, which are formed by the longitudinal edges of the metal strip. The corrugations 1c of the sheet metal element 1 have upper and lower corrugation vertex 1d and corrugation flanks 1e. The waves 1c and their wave crests 1d are straight and parallel to each other and form in plan view with the first edges 1b and longitudinal edges an angle β, which is different from 90 °, preferably at least 60 °, preferably at most 85 ° and for example 70 ° up to 80 °. The apex portions of the waves forming the wave crests are bent in a section extending transversely to the wave crests and / or are provided at the top and at the bottom even with a narrow, flat section.

The sheet metal element 1, which is provided with blanks in the blank state, is now provided in places in several steps with two surfaces 1a with coatings. It is first with the in Fig. 2 apparent coating device 11 a layer of a first coating material 13 applied to both surfaces 1a of the sheet metal element 1. The coating device 11 has a spraying device 15 which has at least one spray nozzle 17, namely at least one spray nozzle 17 on each of the two sides, that is, in the case of both surfaces 1a, of the sheet metal element 1. Each of these spray nozzles has, for example, a slot-shaped spray opening extending transversely to the sheet metal element, which extends approximately over the entire width of the sheet metal element. However, the coating device 11 can also have on both sides of the sheet metal element a plurality of spray nozzles distributed over the width of the sheet metal element, which are arranged, for example, in a row running transversely to the edges 1b of the sheet metal element and which have circular or slot-shaped spray openings. Incidentally, the first coating material can be sprayed, for example, by means of the air supplied to the spray nozzles or without such air. The device 11 still has Guiding and transporting means 19 to guide the band-shaped sheet metal element and in the direction indicated by arrows transport direction 21 between the spray nozzles 17 and to transport past them. The guiding and transporting means 19 may, for example, have fixed guide surfaces and rollers and / or conveyor belts or the like acting on the sheet metal element. The means of transport are in Fig.2 schematically indicated by two opposing rollers 23 which are rotated by a drive device in the direction of arrows 25 and attack on the lower and upper wave crests 1d of the sheet metal element. The first coating material sprayed onto the sheet metal element with the spray nozzles consists of an aqueous dispersion containing dispersed particles of at least one metal oxide, namely aluminum oxide, and possibly also at least one dispersed and / or dissolved additive, such as a binder. The sprayed sheet metal element 1 then has a metallic core 27 formed from the original bare sheet metal element, and coatings 29 which completely cover the core 27 in the two surfaces 1a.

The sprayed-on coatings 29 are initially still wet. The sheet metal element 1 is immediately after the spraying with the first coating material and continuously or after a short time in the Fig. 3 apparent drying device 31 supplied. This has, for example, a furnace 33 with a housing 35. The housing may, for example, an inlet opening 35a and an outlet opening 35b have, so that the sheet metal element 1 can be transported with guide and transport in the transport direction 21 through the housing. These guides and means of transport are like those in Fig. 2 designated 19 and, for example, in turn, at least two in the directions indicated by the arrows 25 directions of rotation driven rollers 23 and / or conveyor belts or the like. The housing 35 of the furnace contains heating means which, for example, have heating elements 37 which are arranged at a distance from the two surfaces 1a of the sheet metal element 1 and can be heated electrically or with a fuel. The coatings 29 are heated in the kiln of the drying device, dried and caked and / or baked and then form a solid and porous layer. This consists, according to the composition of the dispersion sprayed on as the first coating material 13, at least for the most part of at least one metal oxide, namely aluminum oxide.

The porous coating formed by spraying and drying the first coating material 13 can now form the so-called "wash coat" or at least one of the layers of the washcoat. In fact, it is often advantageous, after spraying and drying a layer of first coating material, to spray at least one additional layer of first coating material containing at least one metal oxide onto the sheet metal element and to dry it. The sheet metal element can this still a second time or, if more than two "wash coat" layers are applied, even more times with the in FIGS. 2 and 3 treated facilities are treated. However, it is also possible to provide a system which has two or more coating devices 11 and two or more drying devices 31, so that a sheet metal element 1, for example, continuously transported alternately through a coating device 11 and a drying device 31 can be.

If successively two or more layers of a first coating material sprayed onto the sheet metal element and each heated after being sprayed, dried and baked together and / or baked, the be the same or different to form the different layers of coating materials. In the latter case, the first coating materials sprayed in succession may, for example, contain different concentrations of dispersed metal oxide particles and / or metal oxide particles having different particle sizes and / or different additives. This may, for example, make it possible to produce successively different porous structures with differently sized pores when applying the different layers. However, the first coating material should preferably not contain any catalytically active noble metal in all cases and should serve exclusively for the formation of a porous "wash coat" free of noble metal.

The sheet metal element 1 provided on both surfaces 1a, each with a single-layer or multi-layer coating 29, will now be used in a further treatment step with the in Fig. 4 treated device 41 further treated. This is designed for the mechanical, ie abrasive, removal of the first coating material and has means for removing the coatings 29 formed from the first coating material in places by abrading and / or scraping and / or scraping and / or rubbing off again. The device 41 has, for example, at least two grinding members 45 and guiding and transport means 19. These have, for example, in turn driven rollers 23 and / or conveyor belts or the like and are designed to transport the sheet metal element 1 between the two grinding members 45 therethrough. The grinding members 45 are made, for example, of flexible abrasive belts, each of which has a generally planar portion, at its associated face 1a of the sheet metal member 1 at at least one apex of the vertex, namely at some crests 1d on the outside of each of these crests attacks. By the term "attacking on the outside" is meant that in Fig. 4 Under the sheet metal element 1 located grinding member 45 only on the lower, with respect to the respective wave just outer side of a wave crest attacks and that in Fig. 4 Abrasive member located above only on the upper, with respect to the relevant shaft outer side of a wave crest on this attacks. The abrasive belts are, for example, arranged in such a way and are driven in such a way that their parts acting on wave crests run at right angles to the longitudinal direction of the sheet metal element and are moved. However, it would also be possible to arrange the abrasive belts such that their portions engaging on the sheet metal element are moved parallel to the wave crests or in the longitudinal direction of the sheet metal element.

If the sheet metal element 1 having a coating 29 on both surfaces 1a is moved past them in the transport direction 21 between the grinding members 45, the coatings 29 on the outside of the wave crest are ground away. The sheet metal element then has coated areas 53, in which the coatings 29 are still present, and between them metallic bright, coating-free areas 55. These areas 53, 55 are also clearly in the still closer described FIGS. 6 10 and 10 form strips which extend along the wave crests 1d without interruption over the entire length of the wave crests and thus over the entire width of the band-shaped sheet metal element 1. Each coated area 53 present on one of the two surfaces 1a, which is not located exactly at one end of the sheet metal element 1, extends over almost an entire wavelength from a bare region 55, which is located on the outside of a wave crest 1d, over two corrugation flanks 1e and the inside of the between these wave crests located wave peaks to the bare area at the next wave crest 1d, the outside of which is formed by the same surface 1a. The coated areas 53 thus have, measured transversely to the wave peaks, a substantially greater extent than the bare areas 55 and accordingly occupy larger areas than the bare areas 55.

When the coatings 29 formed by the first coating material 13 have been removed in the manner described on the outside of the well crest, the sheet metal element 1 is the in Fig. 5 apparent coating device 61 supplied. This comprises a trough 63, which contains a bath 65 with a liquid 67, which has a second coating material and / or serves for its formation. The liquid 67 consists, for example, of a solution comprising water and / or an organic solvent and at least one precursor compound of at least one noble metal, for example at least one dissolved salt of at least one catalytically active noble metal, namely, for example, platinum and / or palladium and / or rhodium. Optionally, the liquid 67 may contain, in addition to or in lieu of at least one dissolved precious metal salt, at least one dispersed noble metal precursor compound, such as at least one dispersed noble metal salt, and / or at least one dispersed noble metal. The coating device 61 may, for example, still schematically illustrated guide and transport means 19 with some at least partially driven rollers 23 and / or conveyor belts or the like to move the band-shaped sheet metal element through the liquid 67 therethrough.

When a portion of the sheet metal member is in the liquid 67 of the bath 65 and is moved therethrough, for example, second coating material is applied to the previously formed coated portions. In this case, as the second coating material, for example, at least one noble metal and / or possibly at least one noble metal salt is deposited on the areas 53 of the sheet metal element coated with the first coating material and by sorption, for example by chemisorption and / or possibly physisorption of the first, at least substantially Metal oxide existing coating material adsorbed and bound. The or at least one noble metal and / or at least one noble metal salt is thereby deposited on the previously formed from the first coating material 13, porous coatings and / or incorporated in the pores, the noble metal or noble metal salt then usually no compact layer but forms fine, distributed crystallites. The sheet metal element is heated after the treatment in the liquid still with a not shown drying device and dried. This drying device may for example be designed similar to those in Fig. 3 illustrated drying device. If necessary, a calcination and / or a reduction to hydrogen and / or another chemical treatment can also be carried out during heating and drying. If the sorption process in the bath not directly at least one precious metal, but instead of such or in addition to such first at least one precious metal salt and / or possibly at least one other precursor compound of at least one precious metal was attached to the coatings, the precious metal at the latest separated during the subsequent heating and any calcination and / or reduction and / or other chemical treatment of the remaining components of the noble metal salt, so that only the Precious metal or the precious metals remain in the coatings. The coated areas 53 then have coatings consisting of the porous, "wash coat" and at least one precious metal serving as catalytically active material, for example platinum and / or palladium and / or rhodium, with fine, distributed crystallites.

In the treatment of the sheet metal element 1 in bath 65 is adsorbed only on the first coating material coated with areas 53, but not on the metallic bright areas 55 of the noble metal salt or precious metal. It is therefore applied only there expensive precious metal, where it is then used for the catalytic treatment of exhaust gas. Incidentally, the coatings are applied, for example, such that they are everywhere at least approximately the same thickness in the coated areas 53 everywhere. However, one might instead provide that the thicknesses of the coatings in the general flow direction of the exhaust gas resulting in the use of the sheet metal elements in a catalyst vary in a predetermined manner.

The or each band-shaped, in places coatings with at least one metal oxide and at least one precious metal having sheet metal element 1 is cut with a not shown cutting device in the same size, square-shaped, namely rectangular or square pieces. For example, the band-shaped plate member 1 may have a width equal to one of the desired dimensions of the pieces intended to form sheet member layers, so that pieces having the shape and size of the sheet member sheets can be directly cut off from the band-shaped sheet member 1. However, the sheet metal element 1 may also consist of a relatively wide web and to form the desired pieces or sheet metal layers both transversely and parallel to the first edges 1b are cut. Each of the pieces formed from the sheet metal element 1 has two mutually parallel edges, which are formed by sections of the first edges 1b of the band-shaped sheet metal elements or at least parallel to these first edges and how these are referred to as first edges 1b. Each sheet element layer further has two second, mutually parallel edges which form a right angle with the first edges 1b and in the FIGS. 6 . 8 and 9 are denoted by 1f. The pieces of the sheet metal element 1 or the sheet metal elements are now stacked on each other so that each piece has an in Fig. 6 71 or 73 designated sheet metal element layer of a stack 75 forms of sheet metal element layers. The sheet-metal layers are arranged in stacking such that alternately first sheet-metal layers 71 and second sheet-metal layers 73 follow each other, the waves and crests 1d are bent on different sides of the overlapping first edges 1b. The corrugations and corrugation vertexes of the adjacent sheet-metal element layers 71, 73 then intersect each other at an acute angle other than 90 ° Fig. 9 is denoted by α. The angle α is determined by the relationship α = 2 * (90-β) and is preferably at least 10 °, preferably at most 60 ° and for example 20 ° to 40 °. When the sheet member layers 71, 73 abut each other, they touch each other at the crossing points of the crest 1 d at contact areas formed by parts of the bare portions 55 and in the FIGS. 7 . 9 and 10 denoted by 77.

The stacked sheet metal element layers 71, 73 are now connected to each other in the contact regions 77 cohesively, namely with the aid of in Fig. 7 apparent, electrical welding device 81 welded together by resistance welding. The Welding device 81 has, for example below a fixed electrode 83 and above an electrode 85 which is vertically adjustable and can be pressed with a setting and pressing device against the lower electrode 83, as indicated by arrows 87. The two electrodes have flat, mutually facing surfaces. The welding device 81 also has a power supply device 91 with a power supply connected to the power supply 93, which is connected to at least one capacitor 95. This is in turn connected via a relay device, for example having a switching device 97 with the two electrodes 83, 85.

The stack 75 formed of sheet-metal element layers 71, 73 is arranged for welding together between the two electrodes 83, 85. The upper electrode 85 is then pressed against the stack 75 and the lower electrode 83, whereby the sheet member layers 71, 73 of the stack are pressed against each other. The or each previously charged by the power supply part 93 capacitor 95 is now discharged by temporarily closing the switching device 97 via the electrodes 83, 85 and the stack 75 of sheet-metal element layers. In this case, a strong, but only a short, for example, lasting a few milliseconds current surge is generated, so that the sheet metal elements are welded together at the contact areas 77. Each sheet-metal layer 71 or 73 located between other sheet-metal layers is then at least at each of those wave peaks 1 d extending from a first edge 1 b to the opposing first edge 1 b at a plurality of contact regions 77 distributed along the wave crest Weld connection connected to an adjacent sheet metal element layer, as in Fig. 9 is apparent.

The stack 75 of sheet metal layers forms a solid unit when welding, ie a block, and can only in a metallic, for example, made of stainless steel, in Fig. 8 apparent sleeve 103 are used and together form a catalyst body 101 with this. The sleeve 103 is open at both ends and rectangular or rectangular in cross-section and accordingly has four planar pairs parallel walls, namely two mutually opposite walls 105 and two opposing walls 107. The stack 75 is inserted into the sleeve 103 such that the first edges 1b of the sheet-metal layers are at one end of the sleeve and the other first edges 1b of the sheet-metal layers at the other end of the sleeve and that the second edges 1f of the sheet-metal layers are parallel to the axis and to the hole of the sleeve , The sheet metal layers and the stack formed by these 75 are further dimensioned so that the stack at least approximately backlash and fits snugly into the sleeve and that the second edges 1f of the sheet element layers at least approximately abut the walls 107 of the sleeve. The stack 75 can then be connected in any way with the sleeve and fixed in this. The sheet-metal layers may, for example, be connected to the walls 107 at their second edges 1f by welded joints, namely by welding seams perpendicular to the second edges 1f. These welds can be generated analogously through the walls 107, as it is known from the EP 0 775 808 A and the corresponding US Pat. No. 6,096,682 A is known.

The finished catalyst body 101 is very stable and durable.

The catalyst body 101 may be alone or together with at least one other, the same or similar formed catalyst body used to form a catalyst and are installed in a housing having an inlet and an outlet for the gas to be catalytically treated, namely, for example, for the catalytically cleanable exhaust gas of an internal combustion engine.

The adjacent sheet metal layers 71, 73 of the finished catalyst body define in pairs together a passage for the exhaust gas. Each of these passes runs in the in Fig. 9 indicated by an arrow, general passage direction 111 and / or general exhaust gas flow direction 111 parallel to the walls of the sleeve 103 and perpendicular to the corrugated, first edges 1b of the sheet-metal element layers. As it is particularly evident in Fig. 10 it can be seen, the boundary surfaces of the passages formed by the sheet-metal element layers 71, 73 are almost completely provided with coatings 29 containing catalytically active noble metal. The sheet-metal layers have only on the outside of the crest apex between the successive contact areas along a crest crest 77 very small surfaces in which the exhaust gas comes into contact with portions of the metallic bright, coating-free areas 55. The catalyst body therefore gives a large catalytic effect.

The corrugations and the corrugation vertexes 11 of the sheet metal element layers 71, 73 which are adjacent to each other and are welded in pairs in pairs form, with the general passage direction 111 and / or general exhaust gas flow direction 111, an angle which is equal to half the angle α. The exhaust gas therefore becomes local as it flows through a passage through the shafts and the welded connections present in the passage at the contact regions 77 from the general passage direction and / or the general exhaust gas flow direction distractedly different. As a result, turbulences can be generated in the exhaust gas, which still improve the catalytic effect of the catalyst body.

It can also be several corrugated, strip-shaped sheet metal elements 1 in the manner described with coated areas 53 and metallic bright areas 55 and then produced together with the in Fig. 11 shown plant for the formation of catalyst bodies are further processed. The sheet metal elements 1 may for example be wound on supply rolls or in another form for further processing with the in Fig. 11 be provided to the plant. This system has guide and transport means 19, with which the provided band-shaped sheet metal elements 1 are jointly supplied to a welding device 181 and moved therethrough. The guiding and transporting means 19, like the previously described guiding and transporting means 19, may comprise stationary guide surfaces, rollers and / or conveyor belts and / or the like, schematically showing two rollers 19 as an example, which are driven by a drive device in the directions of the arrows 25 can be turned. The band-shaped sheet metal elements 1 have as in Fig. 1 apparent sheet element 1 waves with obliquely to the longitudinal edges or first edges of the sheet metal elements extending wave crests.

The sheet metal elements 1 are now arranged and superimposed on the welding device 181 supplied that sections of them at the latest when entering the welding device stack 75 of alternately successive sheet metal layers 71 and 73 form, which have intersecting waves and at bare areas on the outer sides of the wave crest abut each other. For example, the welding device 181 has two like the welding device 81 Electrodes 83, 85 with mutually facing, flat surfaces. The upper electrode 85 can be alternately lifted and pressed down with a setting and pressing device in the manner indicated by the double arrow 87. The electrodes are electrically connected to a power supply device, which is, for example, similar in construction to those in FIG Fig. 7 apparent power supply device 91.

During operation of the system, the sheet metal elements 1 are successively transported together in the direction indicated by an arrow 121 transport direction 121 and stepwise to the welding device 181 and between the two electrodes 83, 85 therethrough. In each case, longitudinal sections of the sheet metal elements located between the two electrodes are welded together. In this way, an elongated, rod-like body is successively formed, which is connected to the left of the electrodes with parts of the originally separate sheet metal elements.

In the Fig. 11 Plant shown still has a cutting device 191 with a fixed blade 193 and a movable blade 197, which can be lifted and lowered vertically in the manner indicated by the double arrow 197 way. The formed by welding together sections of the sheet metal elements 1 body is gradually moved by guide and transport means 19 to the cutting device 191 and between the cutting edges 193, 195 therethrough. With the cutting device blocks 199 are then cut off from the body. Each block 199 has a stack 75 of sheet-metal layers 71, 73 welded together. The number of these sheet-metal layers is, of course, equal to the number of sheet metal elements 1 fed to the welding device 181, and is preferably at least 5 and, for example, about 10 to 30.

There can now be several blocks 199 for producing the in Fig. 12 apparent catalyst body 201 can be used. The catalyst body 201 has a sleeve 203, open at both ends, of rectangular or square cross-section, with two opposing walls 205 and two opposing walls 207. The blocks 199 are inserted side by side into the sleeve so that they abut each other directly. The blocks are arranged in such a way that the first edges of their sheet-metal element layers 71, 73 are located at the two open ends of the sleeve and that the second edges of the sheet-metal layers at least approximately abut the walls 207 of the sleeve. The sheet metal layers are then welded at their second edges to the walls 207 of the sleeve. The welding takes place through the walls 207 through analogous as it is from the documents already mentioned EP 0 775 808 A1 and US Pat. No. 6,096,682 A is known. When welding welding connections, namely perpendicular to the second edges of the sheet-metal layers extending welds 211 are generated. The catalyst body 201 then has at least two, for example 5 to 20 or more blocks 199.

It should also be noted that the sheet metal element layers 71, 73 which belong to different blocks 199 may indeed have wave crests facing each other, depending on the arrangement of the blocks in the sleeve. However, belonging to different blocks sheet metal layers are not directly connected to each other at the wave crests. Incidentally, the blocks can also be arranged in the sleeve so that the bare areas of the crest crests of the sheet metal element layers belonging to different blocks do not abut each other at all. The different blocks are essentially only with the sleeve and only indirectly about this, but nowhere directly connected.

It would of course also be possible, only one with the plant according Fig. 11 block 199 to be inserted into a sleeve. The catalyst body formed in this case would then, analogously to the catalyst body 101 shown in FIG. 18, contain only one block of sheet-metal element layers welded together. Conversely, one could use several blocks, which according to the basis of the FIGS. 6 and 7 method described were made of a single sheet metal element or successively made of several sheet metal elements, use in one and the same sleeve and welded to this.

The described methods make it possible to produce sheet-like elements which have partial coatings and in some cases bare metal elements, as well as catalyst elements containing such sheet-metal elements quickly, simply and inexpensively. When the devices 11, 31, 41, 61 and the coating and drying device, if any, for applying and drying at least one additional "washcoat" layer are present in accordance with FIGS. 2 to 5 Having guiding and transport means, a band-shaped sheet metal element from the first coating process to the drying of the applied in the bath 65, second coating material can be processed continuously continuously or quasi-continuously, which allows a particularly efficient production. Incidentally, to those in the FIGS. 2 to 5 and 11 with smooth, circular peripheral surfaces drawn rollers 23 also noted that these could still have in or between the waves of the sheet metal elements engaging teeth. The same applies to the possibly instead of rolls or in addition to such existing conveyor belts.

However, it is also possible to omit certain of the described guiding and transport means, in particular those of the drying device 31 and / or the coating device 61. In this case, at least one sheet metal element or at least one piece of such can then be introduced into the kiln of the drying device 31 or into the bath of the coating device 61 and taken out of the kiln or bath after a designated period of time.

The processes for the production of sheet metal elements and catalyst bodies and the means for carrying out this process can be changed in other ways. The abrasive belt grinding means 45 of the device 41 could be replaced by, for example, grinding wheels or any organs or tools for scraping and / or scraping and / or abrading coating material. The electrodes 83, 85 of in Fig. 11 illustrated welding devices could be replaced by roller-shaped, rotatable electrodes with which the sheet metal elements could be welded during their transport movement.

The sheet metal layers could be materially bonded together at the contact areas instead of resistance welding, another welding process, or brazing or sintering. Further, the sheet member layers of a catalyst body could be formed of portions of a continuous, zigzag, and / or meander-shaped and / or folded sheet metal member rather than separate pieces of a sheet metal member.

The second coating material could possibly be substituted for at least one noble metal and / or at least one precursor compound of a noble metal or in addition to at least one noble metal and / or at least one precious metal precursor compound at least one other catalytically active material and / or at least one other precursor compound of another catalytically active material. The second coating material could, for example, comprise at least one catalytically active base metal and / or at least one oxide and / or salt of a non-precious metal.

Claims (15)

1. Method for the production of at least one sheet metal member (1) for the formation of a catalyst body (101) for a catalytic treatment of gas, in particular of exhaust gas of an internal combustion engine, the sheet metal member (1) having corrugations (1c) with wave summits (1d), a metallic core (27), regions (53) with coatings (29) covering the core (27) and, on the outsides of the wave summits (1d), bare metallic regions (55), at least one bare metallic sheet metal member (1) having corrugations (1c) and two surfaces (1a) facing away from one another being produced, characterized in that a first coating material (13) comprising at least one metal oxide is applied to the two surfaces (1a) of the sheet metal member (1), in that first coating material (13) applied to the outsides of the wave summits (1d) is mechanically removed from the sheet metal member (1), in that a second coating material is then applied to those regions of the surfaces (1a) which were provided with the first coating material (13), and in that the second coating material comprises a catalytically active material and/or serves for the formation of such a material.
2. Method according to claim 1, characterized in that the first coating material (13) is free of noble metal and is porous after consolidation on the sheet metal member (1) and, for example, at least partly consists of aluminium oxide.
3. Method according to claim 1 or 2, characterized in that the first coating material (13) is sprayed on to the sheet metal member (1) and in that the sheet metal member (1) is then heated in order to dry the first coating material (13) and, for example, to solidify it by caking and/or baking after spraying on.
4. Method according to any of claims 1 to 3, characterized in that, after the application of a layer of first coating material (13) to the two surfaces (1a), at least one second layer of a first coating material (13) is also applied to the two surfaces (1a), wherein the successively applied, first coating materials (13) may be, for example, identical or different and/or are, for example, formed and applied in such a way that they give identical or different porous structures.
5. Method according to any of claims 1 to 4, characterized in that the mechanical removal of first coating material (13) is effected by grinding off and/or scraping off and/or scratching off and/or rubbing off.
6. Method according to any of claims 1 to 5, characterized in that the application and removal of first coating material (13) is effected in such a way that the bare metallic regions (55) formed on the outsides of the wave summits (1d) extend without gaps along the entire length of the wave summits (1d), and in that those regions of the two surfaces (1a) which are present between those bare metallic regions (55) of the wave summits (1d) formed by removal of first coating material (13) are provided everywhere with first coating material (13).
7. Method according to any of claims 1 to 6, characterized in that the second coating material comprises at least one catalytically active noble metal and/or at least one precursor compound, for example, at least one noble metal salt, for the formation of at least one catalytically active noble metal, wherein the second coating material comprises, for example, at least one of the noble metals, platinum, palladium and rhodium and/or at least one precursor compound for the formation of at least one of these noble metals.
8. Method according to any of claims 1 to 7, characterized in that, for application of the second coating material, the sheet metal member (1) is introduced into a bath (65) and/or transported through a bath (65) and in that, in the bath (65), at least one noble metal and/or at least one noble metal salt is adsorbed, for example by chemisorption and/or physisorption, on previously applied, first coating material (13) and/or incorporated therein.
9. Method for the production of at least one catalyst body using at least one sheet metal member (1) produced according to any of claims 1 to 8, characterized in that sheet metal member layers (71, 73) adjacent to one another are formed from the sheet metal member (1) or from sheet metal members (1), each of which layers (71, 73) has corrugations (1c) with wave summits (1d), a metallic core (27), coatings (29) and, on the outside of the wave summits (1d), bare metallic regions (55), in that the sheet metal member layers (71, 73) are arranged in such a way that wave summits (1d) of adjacent sheet metal member layers (71,73) intersect one another and rest against one another in contact regions (77) of the bare metallic regions (55), and in that the adjacent sheet metal member layers (71, 73) are joined to one another in the contact regions (77).
10. Method according to claim 9, characterized in that the sheet metal member layers (71, 73) are bonded by material closure, for example, by resistance welding, to one another on joining in the contact regions (77), wherein, for example, an electric current which serves for resistance welding is generated by discharge of at least one electrical capacitor (95).
11. Method according to claim 9 or 10, characterized in that a plurality of strip-like sheet metal members (1) having corrugations (1c), coated regions (53) and bare metallic regions (55) are produced and are combined with one another in such a way that they form sheet metal member layers (71, 73), which rest against one another at intersecting wave summits (1d), in that the sheet metal member layers (71, 73) are joined to one another successively and in that segments of those sheet metal member layers (71, 73) which are joined to one another are cut off, and blocks (199) for the formation of at least one catalyst body (101, 201) are thus formed.
12. Method according to any of claims 9 to 11, characterized in that a plurality of blocks (199) each comprising a stack (75) of sheet metal member layers (71, 73) resting against one another and firmly joined to one another are formed and in that the blocks (199) are assembled to give a catalyst body (201) without the sheet metal members (1) belonging to different blocks (199) being directly joined to one another, wherein, for example, a plurality of blocks (199) are inserted into a sleeve (203) and welded to it.
13. Sheet metal member produced by the method according to any of claims 1 to 8.
14. Catalyst body comprising sheet metal member layers (71, 73) which are adjacent to one another and are formed from at least one sheet metal member (1) produced by the method according to any of claims 1 to 8.
15. Catalyst body according to claim 14, characterized in that it has a sleeve (15) and at least two blocks (199) arranged therein, each of which has a plurality of sheet metal member layers (71, 73), which rest against one another and are firmly joined to one another in contact regions (77) of the wave summits (1d), in that the blocks (199) are firmly joined to the sleeve (203) and in that no sheet metal member layers (71, 73) belonging to different blocks (199) are directly joined to one another at wave summits (1d).

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